Here are the steps for adding outlines to the object:
- in the materials panel, under the "Shaders" tab, set the shaders to "Toon"
- next, go to the "Scene" button, under the "Output" tab turn the "Edges" button on
- finally, click the "Edge Settings" and adjust the edge intensity (Eint) *note: the higher you set this value, the more edges blender will try to outline, so be sure to test your settings by rendering a preview